Valve operating mechanism



Filed Nov.28,' 1930 2 Sheets-Sheet Mmmm Re M R O D mw ww NH a IIC E Y nB mzmv, E s s- E N n w@ ATTORNEY A, F. SCHWENDNER VALVE OPERATINGMECHANISM May 31, 1932,

Filed N0v.28, 1950 2 Sheets-Sheet 2 INVENTOR RF. SCHWENDNER.

`Patented May 31,1932

i UNITED STATES PATENT; orifice;

" f ANTHONY F. SOHWENDNEB OF ESSINGTON, PENNSYLVANIA, ASSIGNOR TOWESTING- HOUSE ELECTRIG MANUFACTURING COMPANY, A CORPORATION OF PENNSYL-f 'VANIA VALVE OPERATING MEcHANIsM Application led November 28, 1930.Serial No. 498,796.

My invention relates to a valvesoperating mechanism for a plurality ofvalves, and it has for its object to provide an improved and simplifiedconstruction thereof.

In accordance with my invention, I provide a fluid pressure relay,enclosed in a separate housing for each valve. A cam shaft extendsthroughthe-housings and carries a cam in each housing for controllingthe relay therein. The cam shaft is op erated by a fluid pressure relay,preferably through a crank arm fixed on the shaft.

The presentvalve operating mechanism is particularly adapted foractuatingthe adf mission valves of a prime mover under control of agovernor responsive to the speed of the priine mover. i

' The above and yother objects areelected by my invention, as will beapparent from f' the following description and claims taken inconnection with the accompanying` drawings forming a part ofthisapplication in which:

Fig. 1 is a diagrammatic view showing the l valve operating mechanismapplied to the steam chest of an elastic fluid turbine;

Fig. 2 is` an end elevational view of the valve operatingmechanism,showing the governor for operating the same in section;

Figs. 3- to 7 are detail views showing the cams for the several valves,the position of the cam shaft being thesame in all of these views; and,

Fig. 8 isa sectional view of one ofthe 'J valves and the relay foroperating the same.

Referring now to the drawings more in detail, I show a steam chest 10associated with an elastic iuid turbine 11. The steam chest includes aprimary valve 13, a secondary valve 14, a tertiary valve 15, aquarternary valve 16, and a quinary valve 17. Each of the valvescommunicates with its corresponding section of thefturbine through aconduit 18. Y

Each of the valves is provided with a fluid pressure relay 19,includingy a separatehousing 20, shown in` detail in Fig. 8. A cam shaft21 extends through the interior of each of the relay housings, and has acam lixed thereon within each of said housings forv operating the relaytherein. llhe cam shaft is rotatably or angularly actuated by agovernor'r22, which is preferably a fluid pressure governor responsiveto the speed of the turbine 11 and which embodies a fluidpressure'relay. Anv impeller 23 is mounted on the turbine rotor shaft 24and delivers to the governor 22, through a yconduit 25; iiuid pressurevaryingV as they square of the speed of the turbine.

The governor 22 is shown in detail in Fig. 2 and includes an ope-ratingpiston26r disposed in a cylinder 27. It is connected through ai lever 28and a link29` to a crank arm 31 fixed on the cam shaft 21.

The piston 26 is formed with an upper tubular extension 32 which extendsthrough vided with a chamber 34 with which the conf duit 25communicates. The piston 26 is thus biased upwardly at all times by thefluid pressure in the chamber 34 acting on the lower end of theextension 33. It is further biased upwardly by a spring 35.

Fluid pressure is admitted to and discharged from the upper end of thecylinder 27 through ports 3G and an annular recess 3T, the latteropening into the hollow interior of the piston. An annular row of ports38 formed in the extension 33 provides communication between the hollowinterior of the piston and the lower end of the cylinder 27. The lattercommunicates with a discharge conduit 39.

A, pilot valve 41, in the form ofV a sleeve closed at its upper end, isdisposed 'within recessL 37. Ity is further provided with an elongatedrecess 45 normally disposed below the recess 37.

The operation of the governor 22 is as follows:

Upon decrease in fluid pressure, the pilot valve 41 is moved downwardlyby the spring 42. The ports 44 move into registry with the recess 37 andfluid pressure from the chamber 34 isadmitted through the ports 44, therecess 37 and the ports 36 to the upper end of the cylinder 27. Thepiston 26 is moved downwardly by said fluid pressure until communicationbetween the ports 44 and the recess 37 is cut off. n moving downwardly,the piston 26 moves the cam shaft 21 in counterclockwise direction,through the lever 28, the link 29 and the crank arm 31.

. Upon increase in fluid pressure in the chamber 34, the pilot valve 41moves upwardly, increasing the tension of the spring 42. The recess 45,upon the upward movement of the pilot valve, places the recess 37 incommunication with the ports 38, so that fluid may flow from the upperend of the cylinder to the lower end. The piston 26 is then movedupwardly by the spring and the fluid pressure acting on the lower end ofthe extension 33 until communication betweeen the recess 45 and therecess 37 is cut off,

' when the Huid in the upper end of the cylinder 27 is locked in andopposes further upward movement of the piston 26. During the upwardmovement of the piston 26, it moves the cam shaft 21 in clockwisedirection.

Referring now to Fig. 8, there is shown a section through the secondaryvalve and its relay 19. The other valves and the relays for operatingrthe same are of similar construction. The relay includes an operatingpiston 46, disposed in a cylinder 47, for actuating the admission valve.The admission of fluid pressure to the cylinder 47 for operating thepiston 46 is controlled by a pilot valve 48 disposed in a bushing 49.

The bushing 49 is provided with ports 51 which communicate with theupper end of the 'cylinder 47 through a passage 52, and

with a row oit ports 53 communicating with the lower end of the cylinder47 through a passage 54. The bushing is further provided with a row ofports 55 disposed above the ports 51 and with a row of ports 56 disposedbelow the ports 53, the ports 55 and 56 communicating with a source offluid pressure through a conduit 57. A row of ports 58 is formed in thebushing between the ports 51 and 53 and communicate with a dischargeconduit 59. The pilot valve 48 is formed with piston portions 50 and 60,which cover the ports 51 and 53 in the cut-off position of the pilotvalve.

- A lever 61 is connected at one end to the piston 46, through pivotalconnection with a. rod 62 fixed to the piston 46. The other end of thelever 61 is connected to the pilot valve 48 by means of a link 63pivoted to the lever and to the pilot valve. A lever 64 is pivoted at anintermediate point to a stationary bracket 65, which serves as a fulcrumfor the lever. yThe left-hand end of the lever 64 is connected to thelever 61 at a point intermediate its connections with the piston and thepilot valve by means of a link 66 pivoted to said levers. The links 63and 66 serve to permit horizontal movement of the connected parts of thelevers 61 and 64 caused by angular movement thereof.

A cam member 67 is fixed on the shaft 21 within the housing 20. Theright-hand end of the lever 64 carries a roller 68 engaging the camsurface of the cam member 67, being urged against the cam b a spring 40acting on the pilot valve 48. he cam member 67 includes an innercircular surface 69, a second circular surface 70, and an inclinedsurface 71 for moving the roller 68 vertically.

The operation of the relay 19 is as follows:

Upon clockwise rotation of the cam member 67 the roller 68 is movedupwardly upon engaging the inclined surface 71. The lever 64 is tiltedin counterclockwise direction, moving the link 66 downwardly. The lattermoves the lever 61 downwardly about its pivotal connection with the rod62, thereby moving the pilot valve 48 downwardly.

The downward movement of the pilot valve 48 places the port-s 55 and 51in communication, admitting fluid under pressure to the upper end of thecylinder 47, in which it acts on the upper side of the piston 46 to movethe same in valve-closing direction. At the same time, the ports 53 and58 are brought into communication, permitting the fluid in the lower endof the cylinder 47 to be discharged through the discharge conduit 59. Asthe piston 46 moves downwardly, it moves the right-hand end of the lever61 downwardly about the pivotal connection with the link 66 and raisesthe pilot valve 48, returning the same to cut-off position.

Upon movement of the cam member in counterclockwise direction, when theinclined surface 71 comes into Contact with the roller 68, the lattermoves downwardly under force of the spring 40. The left-hand end of thelever 64 moves upwardly, permitting the lefthand end of the lever 61 andthe pilot valve 48 likewise to move upwardly. The ports 53 are nowplaced in communication with the ports 56, admitting fluid underpressure to the lower end of the cylinder 47 to raise the piston 46. Thefluid above the piston 46 is discharged through the ports 51 and 58 tothe discharge conduit 59. The piston 46 thereupon moves upwardly toincrease the opening of the admission valve 14, at the same time movingthe pilot valve 48 downwardly to return it to cut-off position throughthe lever 61.

The cylindrical surface 69 of the cam member maintains the roller 68 ina position providing full opening of the admissionvalve, and thecircular surface 70 maintains the roller 68 in a position providingcomplete closing of the admission valve. rl`he opening and closingmovement of the valve is effected during engagement of the roller Withthe inclined surface 71, Which covers a small angle in the movement ofthe cam shaft 21. The time of opening and closing of each valve Withrespect to operation of the governor 22 is determined by the angularposition of the inclined surface 71.

The cam members for the valves 13 to 17 are shown in Figs. 3 to 8,respectively. These figures show the same position of the cam shaft 21,and it Will be noted that the cam member 72 for the primary valveprovides full opening thereof, While the cam member 67 of the secondaryvalve provides complete closing; but upon further counterclockWisemovement, it Will begin movement of the secondary valve in openingdirection. The cam member 73 for the tertiary valve Will re uire furthercounterclockwise movement be 'ore it begins to open the valve, thismovement being equal to the angular movement of the shaft necessary tobring the secondary valve tov full open position. The inclined surfacesof the cam members 74 and 7 5 for the quaternary and quinary valves aresuccessively further spaced from the rollers 68, so that said valveswill open successively after the tertiary valve has opened.

It will be noted that the cam member actuates the pilot valve in thedirection for effecting closing movement of the admission valve. Shouldthe pilot valve tend to stick When the governor is operating invalveclosing direction, the cam member Will provide a positive force formoving the pilot valve, thereby guarding against overspeeding because offailure of the relay to close the admission valve.

The operation of the mechanism as a Whole Will noW be apparent and isasfollows:

Upon increase in load on the turbine and decrease in speed, the Huidpressure developed by the impeller 24 decreases. In response thereto,the piston 26 of the governor 22 moves downwardly to turn the shaft 21in counterclockwise direction. As will be apparent from Figs. 3 to 8,the counterclock- Wise movement of the shaft 21 effects successivedownward movement'of the rollers forY the several admission valves,effecting opening movement thereof in sequence.

Upon decrease in load and increase in speed, the fiuid pressuredeveloped by the impeller 23 is decreased, in response to which thegovernor 22 moves the shaft 21 in clock- Wise direction. The cams on thecam shaft 21 thereupon control the relay of the several is to beunderstood that the invention is not Y so limited. Each valve may bebrought to any desired position at each position of the cam shaft byshaping the cam member accordingly.

From the above description, it Will be seen that I have provided amechanism which is readily adaptable to Widely varying applications. Therate and time of opening of each valve is readily determined by theshape of the cam surface.

lVhile I have shown my invention in but` one form, it Will be obvious tothose skilled in the art that it is not so limited, but is susceptibleof various changes and modifications Without departing from the spiritthereof, and I desire, therefore, that only such limitations shall beplaced thereon as are'imposed by the prior art or as are speciflciallyset forth in the appended claims.

What I claim is:

1. The combination With a plurality of valves, of mechanism foroperating the same comprising a fluid pressure relay for each valve, ahousing for each relay, a cam shaft extending through said housings andhaving a cam thereon in each housing controlling the relay therein, anda fluid pressure relay for actuating the cam shaft.

2. The combination with a plurality of valves, of mechanism foroperating the same comprising ay fluid pressure relay for each valve, ahousing for each relay, a cam shaft extending through said housings andhaving a cam thereon in each housing controlling the relay therein, acrank arm on said shaft, and a fluid pressure relay connected to saidcrank arm for actuating the cam shaft.

3. The combination with a prime mover having a plurality of admissionvalves, of mechanism for operating the same comprising a fluid pressurerelay for each valve, a housing for each relay, a cam shaft extendingthrough said housings and having a cam Y thereon in each housingcontrolling the rethrough said housings and having a cam thereon in eachhousing controlling the relay therein, a crank arm on said shaft, and agovernor responsive to the speed of the prime mover and connected tosaid Crank arm for actuating the cam shaft.

In testimony whereof I have hereunto subscribed my name this 25th day ofNovember,

ANTHONY F. SCHWENDNER.

